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Diffstat (limited to 'TODO')
| -rw-r--r-- | TODO | 109 |
1 files changed, 109 insertions, 0 deletions
@@ -0,0 +1,109 @@ + +LZMA Utils TODO List +-------------------- + +Major missing features + + Memory limits in the command line tool apply only to compression. + + Threading support in the lzma command line tool is still primitive. + It cannot split a file in pieces yet. + + The --list mode isn't implemented in the command line tool. + + Handling of Multi-Block Stream information should be separated + from Stream encoder and decoder. Those would be useful to implement + multi-threaded coding in applications. + + Buffer to buffer coding is not implemented in liblzma. Probably + a naive version should be written first, which would simply wrap + things around lzma_stream. Later, there should be separate buffer + coding functions, that are slightly faster (less memcpy()) and + have smaller memory usage than the functions using lzma_stream. + + libzfile is not implemented. + + LZMA filter doesn't support predefined history buffer. + + +Security + + Search for bugs, especially security related issues. Security is + important in every piece of code in LZMA Utils, but it is extremely + important in the decoder part of liblzma. + + Subblock: If there is LZMA as a Subfilter but without EOPM, can it + trigger infinite loop when Subblock's "Unset Subfilter" flag is hit? + + Similarly, can LZ decoder get stuck in infinite loop if the next + filter in the chain returns LZMA_STREAM_END but the decoded data + doesn't allow finishing the LZ decoding? + + +Reliability + + Create a test suite to be run with "make check". + + Should we use strlimit() and getrlimit() for memory usage limitting? + + +Performance + + Benchmark the CRC code on non-x86 CPUs. Won't have huge effect on + overall speed, but it would still be nice to know what algorithm + variant is the best on different CPUs. + + +Third party support + + Add support for LZMA to various applications. This naturally requires + cooperating with the authors of the specific applications. + * GNU grep and GNU diffutils: BSD grep already uses zlib directly + instead of ugly shell scripts. It would be nice to get similar + feature into relevant GNU tools. With libzfile, multiple + compression formats would be easy to support. + * kioslave for KDE + * Magic for the `file' command + * GNU Midnight Commander + * GNU Texinfo + * The `man' command + * Package managers + + Test the patches already written. The patches should be sent to + upstream developers _once_ LZMA Utils APIs are stable enough (so + people don't need to fix those patches all the time). + + Mandriva has quite a few patches. Some of them are OK, some need + adapting for new LZMA Utils. + + +Documentation + + Revise the man page of lzma command line tool. + + If the Doxygen docs aren't enough, write good Texinfo manual for + liblzma. It's been a long time I've even tried to build the Doxygen + docs, so they may look quite bad at the moment. + + Document LZMA as an algorithm. It would be great to have detailed + description of the algorithm in English. Many people think, that + reading the source code is not the optimal way to learn how LZMA + works. + + +Other + + Some things return LZMA_PROG_ERROR with invalid options, some + LZMA_HEADER_ERROR. These must be checked carefully and made so + that LZMA_HEADER_ERROR is used only when the given option could + make sense in future version of libzma. + + lzma_restrict vs. restrict + + Usage of LZMA_RUN vs. LZMA_FINISH with Metadata coders. + + Port the Deflate implementation from 7-Zip into liblzma. 7-Zip's + Deflate compresses better than zlib, gzip or Info-ZIP. I don't + know if Deflate will be included in .lzma format (probably not), + but it's still useful once we also add support for .gz file format. + |